#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright (C) 2013-14  Stephane Galland <galland@arakhne.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.

#---------------------------------
# IMPORTS
#---------------------------------

# Standard libraries
import weakref
# Include the Gtk libraries
from gi.repository import Gtk

#---------------------------------
# INTERNATIONALIZATION
#---------------------------------

import gettext
_T = gettext.gettext

#---------------------------------
# CLASS InheritButton
#---------------------------------

#
# Gtk button that is managing the inheriting flag.
#
# The inheriting flag indicates if the value(s)
# is inherited or locally set.
#
# This button is displaying an icon that is indicating
# if the inheriting flag is on or off.
#
# When the button state changed (toggled), the associated
# widgets have their enabling states changed.
#
# The attribute 'autolatex_overriding_configuration_value'
# in the associated widgets will reference this button.
# This attribute may be used to detect if the value of
# a given attribute by be taken from the inherited
# configuration or locally set.
#
class InheritButton(Gtk.ToggleButton):
  __gtype_name__ = "AutoLaTeXInheritButton"

  # Constructor.
  # @param container - widget that is containing this button.
  # @param widgets - array of widgets that are associated to this
  #                  button.
  def __init__(self, container, *widgets):
    Gtk.ToggleButton.__init__(self)
    self._is_init = False
    self._container = container
    self._widgets = list(widgets)
    self._inherit_icon = Gtk.Image.new_from_stock(Gtk.STOCK_DISCONNECT, Gtk.IconSize.BUTTON)
    self._override_icon = Gtk.Image.new_from_stock(Gtk.STOCK_CONNECT, Gtk.IconSize.BUTTON)
    self.set_relief(Gtk.ReliefStyle.NONE)
    self.set_active(False)
    #
    for widget in self._widgets:
      widget.autolatex_overriding_configuration_value = weakref.ref(self)

  # Event Handler: Button is pressed or unpressed.
  def on_button_toggled(self, widget, data=None):
    self._update_icon()
    self._update_widget_sensitivities(True)

  # Associate a widget to this button.
  def bind_widget(self, widget):
    if widget:
      widget.autolatex_overriding_configuration_value = weakref.ref(self)
      self._widgets.append(widget)

  # Disassociate a widget to this button.
  def unbind_widget(self, widget):
    if widget and widget in self._widgets:
      self._widgets.remove(widget)
      widget.autolatex_overriding_configuration_value = None

  # Replies if the inheriting flag is on or off.
  def get_overriding_value(self):
    return self.get_active()

  # Set the value of the inheriting flag.
  def set_overriding_value(self, override):
    self.set_active(override)
    if not self._is_init:
      self._is_init = True
      self._update_icon(override)
      self._update_widget_sensitivities(False, override)
      self.connect('toggled', self.on_button_toggled)

  # Update the content of the button (icon and tooltip)
  # according to the value of the inheriting flag.
  def _update_icon(self, is_over=None):
    if is_over is None:
      is_over = self.get_overriding_value()
    if is_over:
      self.set_tooltip_text(_T("Overriding the value in the current configuration"))
      self.set_image(self._override_icon)
    else:
      self.set_tooltip_text(_T("Get the value from the inherited configuration"))
      self.set_image(self._inherit_icon)

  # Update the sensitivity of the button
  # according to the value of the inheriting flag.
  def _update_widget_sensitivities(self, update_container, is_over=None):
    if is_over is None:
      is_over = self.get_overriding_value()
    for widget in self._widgets:
      widget.set_sensitive(is_over)
    if update_container:
      self._container.update_widget_states()

  # Override
  def set_widget_sensitivity(self, is_sensitive):
    override_value = self.get_overriding_value()
    if not override_value:
      is_sensitive = False
    for widget in self._widgets:
      widget.set_sensitive(is_sensitive)
    return is_sensitive

  # Override
  def get_widget_sensitivity(self, widget):
    override_value = self.get_overriding_value()
    if override_value:
      return widget.get_sensitive()
    else:
      return False